Tiêu đề DPP-6 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 6 1 (a) White vitriol is ZnSO4.7H2O. 2 (a) No in iron complex has +1 oxidation number. 3 (b) Mn 2+ is most stable as it has half-filled d-orbitals. 4 (c) ZnCl2 ∙ 2H2O ∆ Zn(OH)Cl + HCl + H2O Zn(OH)Cl→ZnO + HCl 5 (c) 3Fe(CN)2 +4Fe(CN)3→Fe4 [Fe(CN)6 ]3 or Fe7C18N18 Prussian blue 6 (a) CrO2― 4 has no unpaired d ― electron. 7 (a) La(OH)3 is more basic than Lu(OH)3. This is because ionic size of La 3+ ion is more than L u 3+ ion 8 (d) Cerium is commonly used in manufacture of alloys of lanthanide. It is also used in dying cotton or fabrics, for scavenging oxygen and sulphur from other metals and also used as catalyst. 9 (a) —do— 10 (d) It is a reason for the given fact. 11 (d) It is a fact. 12 (b) Zn does not show corrosion. 13 (c) The process is called hardening of steel and it develops hard and brittle nature in steel. Topic :- THE D-AND F-BLOCK ELEMENTS Solutions
14 (c) Lowest m.p. among all metals is of Hg (⎯38.9C). 15 (d) The temperature of the slag zone in the metallurgy of iron using blast furnace is 800-1000° C. 16 (b) The phenomenon is called spitting of Ag. 17 (c) Cu2O has completely filled d ― orbitals in Cu + and thus, does not show (d ― d) transition. 18 (c) Hg(OH)2 does not exist. 19 (d) K2HgI4, a colourless complex, is formed, 4KI + HgCl2⟶K2HgI4 + 2KCl 20 (a) The atomic weight of Co, Ni and Fe are 59.90, 58.60, 55.85 respectively. Therefore, Co > Ni > Fe is the correct sequence of atomic weights
ANSWER-KEY Q. 1 2 3 4 5 6 7 8 9 10 A. A A B C C A A D A D Q. 11 12 13 14 15 16 17 18 19 20 A. D B C C D B C C D A